Change Outlook's color theme in three steps

Open Outlook and go to File > Options (Windows) or Outlook > Preferences (Mac). In the left sidebar, select General. Under the Personalization section, you'll see a dropdown menu labeled Office Theme or Color Mode. Choose from the available options — typically Colorful, Dark Gray, Black, or Light — and click OK to apply the change immediately.

The theme you select changes the background color of your ribbon, sidebar, and message pane. It does not change the color of individual emails or how they display in your inbox. If you want to change how specific emails look or organize them by color, you'll use a different feature called categories or flags, which work separately from the overall theme.

Key Takeaways

  • Outlook's color theme is found in File > Options > General > Personalization on Windows, or Outlook > Preferences > General on Mac.
  • The built-in themes are Colorful (default), Dark Gray, Black, and Light — you cannot create a custom color or pick individual RGB values.
  • Changing the theme affects the interface background but not the color of emails themselves in your inbox.
  • If you want to color-code individual emails, use categories or flags instead of changing the overall theme.
  • The change takes effect immediately and applies to all folders and views in Outlook.

Where to find the theme settings on Windows

On Windows, the theme menu is in the core Outlook settings. Click File in the top-left corner, then select Options at the bottom of the menu. A window titled "Outlook Options" will open. On the left side, click General. Scroll down until you see the Personalization section — it's usually near the middle of the page.

The Office Theme dropdown is the main control. Click it to see all available themes. Select the one you want and click OK at the bottom of the Outlook Options window. Your choice saves automatically and applies to Outlook the next time you open it, or immediately if Outlook is already running.

Where to find the theme settings on Mac

On Mac, the path is slightly different. Click Outlook in the top menu bar, then select Preferences. A new window will open. Look for General in the list on the left side and click it. Scroll down to find the Personalization or Color Mode section.

Mac versions of Outlook sometimes label this setting differently depending on which version you have. If you don't see "Office Theme," look for "Appearance" or "Color Mode." The dropdown will show the same theme options as Windows. Select your choice and close the Preferences window — the change applies right away.

What each theme looks like and when to use it

Colorful is the default theme and uses a white or light background with blue accents in the ribbon and sidebar. It's the easiest on the eyes during the day and works well if you spend long hours reading emails with a lot of text. Dark Gray uses a medium gray background and is easier on the eyes in dim lighting. Black is the darkest option and reduces screen brightness the most, which some people prefer in the evening or in dark rooms.

Light is similar to Colorful but with even fewer colors and a cleaner look. It's useful if you find the default theme too busy. None of these themes change the content of your emails — they only change how the Outlook window itself looks. If you switch themes and then switch back, your emails and folders remain exactly as they were.

Using categories and flags to color individual emails

If you want to mark specific emails with color rather than change the entire Outlook interface, use categories or flags. Right-click any email in your inbox and select Categorize (Windows) or look for the flag icon in the toolbar. You can assign a color-coded category to that email. Categories show up as colored labels next to the email subject line and help you organize and find emails by topic or priority.

Flags work similarly but are simpler — they just mark an email with a colored flag (usually red, orange, yellow, green, or blue depending on your version). Flags are useful for marking emails that need action, while categories are better for organizing emails by type or project. Both features work independently of the theme you choose for your overall Outlook appearance.

Troubleshooting theme changes that don't appear

If you change the theme but don't see the change, close Outlook completely and reopen it. Sometimes the change doesn't display until you restart the application. If you're on a work computer, your IT department may have locked the theme setting, which means you won't be able to change it — in that case, you'll see a message saying the setting is managed by your organization.

On Mac, if the theme doesn't change after you close Preferences, check that you're running a recent version of Outlook. Older versions have limited theme options or may not support dark mode at all. You can check your version by clicking Outlook > About Outlook in the menu bar. If you're several versions behind, updating Outlook may give you more theme choices.

Frequently Asked Questions

Can I create my own custom color theme?

No. Outlook only offers the four built-in themes: Colorful, Dark Gray, Black, and Light. You cannot pick custom colors or create a theme from scratch. If none of the built-in options work for you, dark mode (Dark Gray or Black) is usually the closest alternative to what you're looking for.

Does changing the theme affect how my emails look when I send them?

No. The theme only changes how Outlook looks on your computer. When you send an email, the recipient sees it in their own email client with their own theme applied. Your theme choice has no effect on how the email appears to anyone else.

Will changing the theme delete or move any of my emails?

No. Changing the theme is purely visual and does not touch any of your email data, folders, or settings. All your emails stay exactly where they are, and you can switch themes back and forth without any risk of losing anything.

Why does my theme keep changing back to the default?

If you're on a work computer, your organization's IT policies may reset the theme automatically. Check with your IT department to see if theme settings are managed. On personal computers, this is rare, but restarting your computer and then changing the theme again usually fixes it.